Add helper function to explain general_metadata queries

[vshnvii]

Summary

This PR introduces a helper function to explain what the general_metadata query does in a simple and user-friendly way.

Motivation

While exploring the malariagen_data API, I noticed that understanding what a function does may not always be straightforward, especially for users who are not very familiar with the codebase or programming in general.

This small addition aims to improve usability by providing a way to quickly understand what kind of data is being retrieved and what the query represents.

Changes

• Added a helper function explain_general_metadata_query
• The function prints a short explanation of:
  • which sample sets are being queried
  • what kind of metadata is returned

Example

explain_general_metadata_query(["AG1000G-BF-A"])

This will fetch metadata for sample sets: ['AG1000G-BF-A']
The metadata includes fields like sample_id, location, collection date, etc.